Development of Measurement Instruments for Space-Time Density Distribution of Floating Small Particles

为了开发测量漂浮小颗粒尺寸和密度的仪器，本研究对以下三种方法进行了研究。[1]利用激光扫描法的微小粒子的测量方法该方法是通过检测在照射下通过激光束的微小粒子的光散射而获得的随时间变化的随机脉冲信号的振幅直方图，导出粒子密度和粒子尺寸谱。具体研究内容包括：（1）激光扫描光学系统和检测系统的优化设计、结构和改进;（2）散射光时间积分强度空间分布的显示方法、粒度和密度的分析;（3）被动测量颗粒的评价和仪器的总体评价。在这些结果的基础上，测量仪器实际上是c 关于我们 构造的。[2]利用运动透射光栅的微小颗粒光学测量方法该方法被称为空间滤波测速法，是利用光电探测器通过透射光栅探测运动微小颗粒的光学图像，通过分析电信号的频率分布来确定颗粒的速度、尺寸和密度。具体研究了以下几个方面：（1）方法的原理和理论;（2）用两个旋转透射光栅测量二维速度;（3）传像光纤在空间滤波测速中的应用;（4）空间滤波测速中颗粒密度和尺寸的测量。在这些结果的基础上，几个速度计的开发和建设。[3]采用散斑相关技术测量细颗粒尺寸的方法该方法基于双曝光散斑照相术，并测量在两种不同激光照射下从粉末床的同一表面产生的两个散斑图案之间的相关程度。进行了初步研究，以验证该方法的实用性，并显示其使用的可能性，在一个在线测量过程。少

For the purpose of developing measurement instruments for the size and density of floating small particles, the present study investigates the following three methods.[1] Measurement method of small particles using a laser-beam scanning method The method is to derive the particle density and the particle-size spectra from the amplitude histogram of time-dependent random pulse signals obtained by detecting the light scattering from the small particles passing through the laser beam under illumination. Actual studies were performed in the following items: (1) optimum designs of the laser-beam scanning optical system and the detecting system, and their construction and improvement, (2) display method for the spatial distribution of time-integrated intensity of the scattering light, and analysis of the particle size and density, and (3) evaluation of passibly measuring particles and overall evaluation of the instrument. On the basis of these results, a measurement instrument was actually c … More onstructed.[2] Optical measurement method of small particles using moving transmission gratings The method, which is called spatial filtering velocimetry, is to detect, by means of a photodetector, the optical images of moving small particles through a transmission grating and to determine the velocity, size and density of particles by analyzing the frequency distribution of electric signals. Actual studies were conducted in the following items: (1) principle and theory of the methods, (2) measurements of the two-dimensional velocity using two rotating transmission gratings, (3) application of an image fiber to spatial filtering velocimetry, and (4) measurements of the particle density and size in spatial filtering velocimetry. On the basis of these results, several velocimeters were developed and constructed.[3] Measurement method of fine particle size using a speckle correlation technique The method is based on double-exposure speckle photography and is to measure the degree of correlation between the two speckle patterns produced from the same surface of a powder bed under two different laser illuminations. A preliminary study was performed to verify the usefulness of the method and to show the possibility of its use in an on-line measuring process. Less